What means under-modulation?

Under-modulation occurs when the maximum amplitude of the message signal or modulating signal is less than the maximum amplitude of the carrier signal (Am < Ac). The modulation index is the ratio of the maximum amplitude of the message signal to the maximum amplitude of carrier signal.

What is difference between demodulation and modulation?

The key difference between modulation and demodulation is that modulation is done at the transmitter side while demodulation is done at the receiver side of a communication system. Modulation is basically done to transmit data to longer distance whereas demodulation is done to regain the original message signal.

What causes Overmodulation?

When the input telecommunication exceeds the required value, it results in over modulation. Over modulation can take place in both AM and FM systems.

What is the effect if modulation index is greater than 1 over-modulation?

When the value of the modulation index goes more than one then it causes overmodulation which leads to distortion and causes the bandwidth to not be preserved. The modulation index is the amount of modulation that is done on a carrier signal.

How can we avoid over-modulation in AM?

Over-modulation occurs when this maximum level is exceeded, and the result is DISTORTION, or even equipment damage. LIMITERs are used to prevent over-modulation and PEAK CLIPPING.

What will be the problem when AM is over-modulated?

If over-modulation does occur the carrier is chopped up and the modulation no longer resembles its modulating signal. At the receiving end the signal will be very distorted and unreadable – but more important, the over-modulated signal will have an increased bandwidth and will be rich in unwanted harmonics.

What is difference between FM and PM?

Phase Modulation is a modulation in which the phase of the carrier wave changes according to the instantaneous amplitude of the modulating signal keeping amplitude and frequency constant….Difference between Frequency Modulation and Phase Modulation :

S.NO.	Frequency Modulation	Phase Modulation
10.	In FM, received signal is of high quality.	In PM, received signal is of low quality.